The Journal of Korean Society for Radiation Therapy (대한방사선치료학회지)
- Volume 12 Issue 1
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- Pages.91-104
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- 2000
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- 1598-8449(pISSN)
Study on 6 MV Photon beam Dosimetry by Asymmetric Collimator Variation of Linear Accelerator
6MV 선형가속기의 비대칭 조사야의 변화에 따른 선량분포
- Yoon, Joo-Ho (Dept. of Radiation Oncology. Kosin Medical College, Kosin University) ;
- Lee, Chul-Soo (Dept. of Radiation Oncology. Kosin Medical College, Kosin University) ;
- Yum, Ha-Yong (Dept. of Radiation Oncology. Kosin Medical College, Kosin University)
- Published : 2000.12.01
Abstract
Recently linear accelerator in radiation therapy in asymmetric field has been easily used since the improvement and capability of asymmetrical field adjustment attached to the machine. It has been thought there have been some significant errors in dose calculation when asymmetrical radiation fields have been utilized in practice of radiation treatments if the fundamental data for dose calculation have been measured in symmetrical standard fields. This study investigated how much the measured data of dose distributions and their isodose curves are different between in asymmetrical and symmetrical standard fields, and how much there difference affect the error in dose calculation in conventional method measured in symmetrical standard field. The distributions of radiation dose were measured by photon diode detector in the water phantom (RFA-300P, Scanditronix, Sweden) as tissue equivalent material on utilization of 6 MV linear accelerator with source surface distance (SSD) 1000 mm. The photon diode detector has the velocity of 1 mm per second from water surface to 250 mm depth in the field size of